JP2005147723A - Reactor building and method for constructing it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To downsize a reactor building and shorten the construction period of it by decreasing the width of a gap between a reactor containment vessel and a biological shielding wall installed for radiation shield around a reactor containment vessel. <P>SOLUTION: In the reactor building 4 consisting of the reactor containment vessel 2 and the biological shielding wall 3 installed outside the vessel 2, a horizontal gap 6 between the lower tiers of the vessel 2 and the wall 3 is set at a width (50mm to 300mm) narrower than a width of 800mm which is accessible to human workers. Moreover, a module whose constituting members are the lower tiers of the vessel 2 and the wall 3 is formed by setting the horizontal gap 6 between the lower tiers of the vessel 2 and the wall 3 at a narrow width (50mm to 300mm) and the constituting members are installed in the lump in an installation position by hoisting the module and carrying it in the position. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a reactor building in which a nuclear reactor containment vessel and a biological shielding wall are installed, and a construction method thereof.

  A reactor building of a boiling water reactor that uses light water as a coolant includes a reactor containment vessel and a biological shielding wall that covers the outer periphery of the reactor containment vessel. The reactor containment vessel is made of a steel plate and is self-supporting, and a biological shielding wall is provided around the outer periphery of the reactor containment vessel via a space gap (see, for example, Patent Document 1).

  Generally, between the reactor containment vessel and the biological shielding wall, in order to secure a working space for the reactor containment vessel and the biological shielding wall and to secure work space such as painting of the reactor containment vessel, A gap width of about 800 mm is secured between the biological shielding walls as a space accessible to personnel.

  Also, when constructing a reactor containment vessel and a steel biological shielding wall, the reactor containment vessel main body block and the steel biological shielding wall block divided in the vertical direction and the circumferential direction are lifted and moved together. At the construction position, the reactor containment vessel main body block and the steel biological shielding wall block are placed on or in a predetermined position in the circumferential direction, and the reactor containment vessel main body block and the steel biological shielding wall block are simultaneously surrounded. A construction process of a reactor building that is installed in a vertical direction is known (for example, see Patent Document 2).

Japanese Patent No. 2934341 JP-A-7-260978

  According to the construction method in which a gap of about 800 mm is set between the reactor containment vessel and the biological shielding wall as in the conventional example, the biological shielding wall and the atoms including the biological shielding wall are secured to secure the gap. The furnace building becomes larger.

  In addition, since the steel biomedical shielding wall has a large factor for obtaining a radiation shielding function from the steel plate, the bioshielding wall steel plate is thick and large in weight. In this case, the method of assembling the biological shielding wall and the reactor containment vessel into a cylindrical shape and then hanging it up to the construction position and assembling the hoisting machine by making the biological shielding wall and the reactor containment vessel into a cylindrical shape There are cases in which the weight exceeds the work capacity of and cannot be adopted.

  Therefore, when the biological shielding wall and the reactor containment vessel are suspended and installed at the construction position at the same time, the reactor containment vessel and the biological shielding wall are divided into a plurality of parts in the vertical direction as well as in the circumferential direction. As a result, the construction work process is prolonged and the work of aligning the steel sheets in the circumferential direction at the construction position and the work of welding the combined parts occur. It is necessary to set a gap of 800 mm.

  In addition, although it can be assumed that the biological shielding wall is made of reinforced concrete, it takes time to install the rebar, and the work of installing and removing the concrete formwork is extraneous and the work is done. In addition, it is necessary to set a gap of about 800 mm between the reactor containment vessel and the biological shielding wall.

  Thus, conventional reactor buildings are large and tend to prolong the construction period.

  Accordingly, an object of the present invention is to achieve downsizing of the reactor building and shortening of the construction period.

  A reactor building according to the present invention includes a steel plate containment vessel, a bioshield wall made of steel plate concrete surrounding the reactor containment vessel, an outer periphery of a cylindrical portion of the reactor containment vessel, and the bioshield wall A reactor building having a gap of 50 mm to 300 mm formed between the first and second cylindrical steel plates constituting the reactor containment vessel and steel plate concrete as a method of constructing the reactor building The second steel plate is located with a gap of 50 mm to 300 mm around the outer periphery of the first steel plate between the inner cylindrical shape and the outer cylindrical multi-cylindrical second steel plate constituting the living body shielding wall made of metal. The module is arranged in such a manner that the module is suspended and installed at the construction position of the reactor containment vessel and the biological shielding wall, and then the reactor containment vessel and the biological shielding wall portion above the module are installed. Set and the second reactor construction method of a building of injecting concrete between the steel and the inner and outer is adopted.

  According to the present invention, the construction period of the reactor building can be shortened and the reactor building can be downsized.

  As shown in FIG. 1, a reactor building 4 of a nuclear power plant that employs a boiling water reactor using light water as a coolant includes a reactor containment vessel 2 on the basic mat 15 of the reactor building 4 and the outside. A surrounding room 33 is included. The surrounding room 33 and the reactor containment vessel 2 are isolated from each other via a biological shielding wall 3 that shields radiation from the reactor containment vessel 2 side. When the living body shielding wall 3 includes up to the upper lid, the cross section is shown by hatching in FIG. The vertical wall surface portion of the biological shielding wall 3 has a cylindrical shape in a horizontal section, a hemispherical atom in which the lower horizontal section is cylindrical and the upper part is faced in the cylindrical range. A furnace containment vessel 2 is accommodated. The reactor containment vessel 2 is made of a steel plate, and the biological shielding wall 3 has a steel plate concrete structure (SC structure) composed of two steel plates and concrete filled inside thereof.

  The vertical portion of the biological shielding wall 3 has a double cylindrical structure of a cylindrical outer steel plate 14b opposite to the cylindrical inner steel plate 14a facing the reactor containment vessel 2, and includes an inner steel plate 14a and an outer steel plate 14b. Are coupled to each other so that the distance between the steel plates on both sides does not change. A concrete liquid is provided between the steel plates on both sides in a solidified state to achieve a desired radiation shielding function between the steel plates and the concrete. The upper horizontal portion (top slab 21) of the biological shielding wall 3 is constructed with a half SC structure. In the half SC structure, half of the thickness of the horizontal portion is composed of the steel plate on the lower surface and the concrete thereon, and the thickness of the half above it is composed of reinforced concrete. With this configuration, a desired radiation shielding function is achieved also in the upper horizontal portion of the biological shielding wall 3. Since the upper horizontal portion of the biological shielding wall 3 has various pools at the upper portion, the thickness range of the upper half of the horizontal portion is made of reinforced concrete and the thickness range of the lower half is made of steel plate concrete. It is preferable to ensure an appropriate strength as a structure. In this case, when the lower half thickness range is made of steel plate concrete, the steel plate is adopted on the lower surface facing the reactor containment vessel 2, and the steel plate has channel steel ribs on the wall thickness side. Make sure to install and withstand the concrete casting pressure.

  In the reactor containment vessel 2, a cylindrical reactor pressure vessel foundation 5 is installed at the bottom at the center. A reactor pressure vessel 1 is installed on the reactor pressure vessel foundation 5. A cylindrical γ-ray shielding wall 22 installed on the reactor pressure vessel base 5 is disposed around the outer periphery of the reactor pressure vessel 1, and the γ-ray shielding wall 22 surrounds the outer periphery of the reactor pressure vessel 1. ing. A diaphragm floor 27 is passed between the reactor pressure vessel foundation 5 and the reactor containment vessel 2. The pressure suppression chamber 8 isolated by the diaphragm floor 27, the reactor pressure vessel base 5 and the reactor containment vessel 2 is isolated from other spaces in the reactor containment vessel 2, and the reactor containment vessel 2 at the time of the accident. A pipe for drawing the steam in the reactor and the excess steam in the reactor pressure vessel 1 from the reactor containment vessel 2 and the reactor pressure vessel 1 is connected, and the steam is condensed by the pool water in the pressure suppression chamber 8. ing.

  The inside of the reactor pressure vessel base 5 and the inside of the room 33 outside the living body shielding wall 3 are connected by a tunnel 31 through which equipment and personnel come and go. In this tunnel 31, the atmosphere in the reactor containment vessel 2 is prevented from coming out into the room 33 by a double door to prevent the atmosphere from coming and going. A main steam pipe 32 that leads from the reactor pressure vessel 1 to the turbine generator is connected to the reactor pressure vessel 1, and a valve 34 is installed in the middle thereof. The main steam pipe 32 is routed through a pipe penetration structure extending from the reactor containment vessel 2 to the room 33 outside the biological shielding wall 3, that is, through the penetration 16.

  The penetration 16 that is a pipe penetration structure is a cylindrical structure having a diameter through which the main steam pipe 32 can pass, and has a structure that prevents the circulation of the atmosphere between the reactor containment vessel 2 and the outside of the reactor containment vessel 2. It is used as one member. Similarly, a cable penetration structure through which cables from the reactor containment vessel 2 to the room 33 outside the living body shielding wall 3 penetrate, that is, the penetration 16 for the cable, is also provided. In addition, an openable / closable lid 35 serving as a biological shielding wall 3 is installed on the upper part of the reactor containment vessel 2.

  The reactor building 4 is provided with a temporary equipment storage pool 36, a fuel storage pool 37, an operation floor 38, and a roof 39 of the building as a matter of course.

  The reactor containment vessel 2 has a cylindrical shape from a low part to a height near the diaphragm floor 27 as shown in FIGS. This is referred to as the lower containment vessel 2 for convenience. The reactor containment vessel 2 portion above the lower stage has a hemispherical appearance with the bowl lying down, as shown in FIGS. This will be referred to as the upper reactor containment vessel 2 for convenience. The upper end of the lower stage of the reactor containment vessel 2 and the lower end of the upper stage are welded and integrated. At the top of the upper stage of the reactor containment vessel 2, a removable lid 40 of the reactor containment vessel 2 is installed.

  The horizontal gap 6 between the cylindrical shape portion of the reactor containment vessel 2 and the biological shielding wall 3 is designed by selecting from numerical values in the range of 50 mm to 300 mm. Above the cylindrical shape portion, the horizontal gap 6 between the reactor containment vessel 2 and the biological shielding wall 3 is larger than the value selected from the range of 50 mm to 300 mm. However, the reason for the large numerical value is that the diameter in the horizontal direction becomes smaller as the upper stage of the containment vessel 2 goes upward, whereas the inner diameter of the biological shielding wall 3 is from the low part to the height from the top slab 21. This is because it has not changed.

  The living body shielding wall 3 of the present embodiment is not a reinforced concrete structure that requires the installation or removal of a concrete formwork, but is made of steel plate concrete that does not require the installation or removal of such formwork. It is not necessary to provide a horizontal gap 6 of about 800mm as a work space for installing and removing the formwork between the body 2 and the biological shielding wall 3, and the shape of the reactor containment vessel 2 due to thermal expansion, rapid increase in pressure, and behavior during an earthquake A horizontal gap 6 of 50 mm to 300 mm is formed between the reactor containment vessel 2 and the inner steel plate 14a of the biological shielding wall 3 without taking into account the change absorption and the like and securing the work space for the installation and removal of the formwork. Provided.

As described above, since the horizontal width of the gap 6 formed between the outer periphery of the cylindrical portion of the reactor containment vessel 2 and the biological shielding wall 3 is reduced from 800 mm to 50 mm to 300 mm, 50 mm to 300 mm.
The dimension equivalent to twice mm can be reduced in the vertical and horizontal directions in the horizontal plane of the reactor building 4 to reduce the site area and construction area of the reactor building 4.

  In the entire circumference between the lower part of the reactor containment vessel 2 and the lower part of the biological shielding wall 3, as shown in FIG. 3, absorption of deformation due to thermal expansion of the reactor containment vessel 2 and the reactor containment vessel 2 A sand cushion 9 made of sand is provided to release thermal stress. In order to increase the volume of the sand cushion 9 in the horizontal direction and secure a space for installing the sand cushion 9, the lower part of the biological shielding wall 3 is partially cut out in the thickness direction of the biological shielding wall 3 to secure a space for providing the sand cushion 9. did. Thereby, even when the gap 6 width between the reactor containment vessel 2 and the biological shielding wall 3 is narrowed, the sand cushion 9 can be installed. Moreover, since the notch part of the lower part of the biological shielding wall 3 is filled so that sand may shield a radiation, the functional shielding problem in the sand cushion 9 part does not deteriorate.

  An example of the construction method of such a reactor building 4 will be described below. First, the foundation mat 15 of the reactor building 4 is made on the bedrock. Next, the lower liner of the reactor containment vessel 2 is provided on the basic mat 15. The module 17 is installed so as to cover the lower liner.

  As shown in FIG. 2, the module 17 is made of a steel-made cylindrical containment vessel 2 lower stage, and an inner steel plate 14 a and an outer steel plate of the biological shielding wall 3 disposed around the lower stage of the reactor containment vessel 2. 8b and a cylindrical penetration 16 that is fixed to the lower stage of the reactor containment vessel 2 and passes through a through hole 41 provided in the inner steel plate 14a and the outer steel plate 14b, as shown in FIG. As shown in FIG. 8, the through hole 41 is formed to have a larger diameter than the outer diameter of the penetration 16, and the edge of the through hole 41 and the penetration 16 are brought into contact with each other during the loading operation to the construction position. It is preventing. The inner steel plate 14a and the outer steel plate 14b of the biological shielding wall 3 are fixed with steel plates set on both sides so that the distance between the steel plates on both sides, about 1.5 meters to about 2 meters, does not change. It is.

  The heights of the inner steel plate 14a and the outer steel plate 14b of the biological shielding wall 3 are set lower than the lower level of the reactor containment vessel 2 as shown in FIG. That is, the upper end of the lower stage of the containment vessel 2 is positioned higher than the upper ends of the inner steel plate 14a and the outer steel plate 14b of the biological shielding wall 3. By giving such a height difference, consideration is given so that welding joint between the upper end of the lower part of the containment vessel 2 and the lower end of the upper part of the containment vessel 2 where welding joining from both sides is required can be easily achieved. It is.

The lower stage of the reactor containment vessel 2, the inner steel plate 14a, the outer steel plate 14b, and the penetration 16 of the biological shielding wall 3 are assembled so that they can be lifted together. That is, as shown in FIG. 8, a steel mounting jig 23 is welded and fixed to a suspension balance 19 in which H-shaped steels are radially combined in eight horizontal directions, and the bottom of the reactor containment vessel 2 and the biological shielding wall 3 are fixed. The inner steel plate 14a and the outer steel plate 14b are fixed to the nearest mounting jig 23 by welding. In this way, each part constituting the module 17 is integrated by the suspension balance 19 and the mounting jig 23 so as not to be separated. In this integrated state, each part which comprises the module 17 is fixed to the installation position relationship. A wire rope 20 is coupled to the suspension balance 19. By pulling the wire rope 20 upward with a crane, the lower stage of the containment vessel 2, the inner steel plate 14 a, the outer steel plate 14 b and the penetration 16 of the biological shielding wall 3 are defined. The integrated module 17 can be lifted together by a crane. Further, as shown in FIG. 9, a buffer member 42 is installed between the lower stage of the reactor containment vessel 2 as the module 17 and the inner steel plate 14 a of the biological shielding wall 3 so that they do not come into contact with each other.

  The module 17 is in a state where the relative position relationship between the lower stage of the containment vessel 2 and the inner steel plate 14a, the outer steel plate 14b and the penetration 16 of the biological shielding wall 3 is the same as the relative position relationship at the time of installation. It is integrally made with a suspension balance 19 and a mounting jig 23 at a location adjacent to the construction site. Before the module 17 was made, the bottom of the containment vessel 2 and the inner steel plate 14a, the outer steel plate 14b, and the penetration 16 of the biological shielding wall 3 were subjected to work such as painting as much as possible at the present time after installation. Save work as much as possible.

  The module 17 integrated with the suspension balance 19 and the mounting jig 23 is lifted by a crane, and is carried on the lower liner on the foundation mat 15 of the reactor building 4 and suspended. During the transportation, the lower stage of the containment vessel 2 and the inner steel plate 14a and the outer steel plate 14b of the biological shielding wall 3 are fixed by the suspension balance 19 so that their positions are maintained. 17 and the shape of each component constituting the module can be suppressed.

  When the module 17 is suspended, the welding balance between the lower stage of the containment vessel 2 and the inner steel plate 14a and the outer steel plate 14b of the biological shielding wall 3 with respect to the mounting jig 23 is separated and the suspension balance 19 is removed from the module 17. At the same time, the lower stage of the reactor containment vessel 2 and the inner steel plate 14a and the outer steel plate 14b of the biological shielding wall 3 are set, that is, installed on the base mat 15 side. Next, as shown in FIG. 9, the steel plate portion of the reactor pressure vessel 1 foundation 5 assembled in a cylindrical shape and the steel member such as the reinforced steel frame of the diaphragm floor 27 are suspended in the lower stage of the reactor containment vessel 2 by a crane. Set and construct concrete for the reactor pressure vessel foundation 5 and the diaphragm floor 27. Furthermore, the cylindrical γ-ray shielding wall 22 is set by hanging down on the reactor pressure vessel foundation 5 with a crane, and the concrete of the γ-ray shielding wall 22 is constructed. A main steam pipe 32 in the range in the reactor containment vessel 2 and a valve 34 attached thereto are attached to the γ-ray shielding wall 22 and are suspended simultaneously with the γ-ray shielding wall 22.

  Next, the portion of the reactor containment vessel 2 made of steel plate above the lower stage of the reactor containment vessel 2, that is, the upper stage of the reactor containment vessel 2 is suspended by the crane to the upper end of the lower stage of the reactor containment vessel 2. After that, the lower end of the upper stage of the containment vessel 2 and the upper end of the lower stage of the containment vessel 2 are welded and joined from both the inside and outside of the containment vessel 2. At the time of this welding, since the joint line between the lower end of the upper stage of the containment vessel 2 and the upper end of the lower stage of the containment vessel 2, that is, the welding line is not surrounded by each steel plate of the biological shielding wall 3, the welding is performed. In addition to being sure, it is easy to inspect the weld.

  Next, the steel lid 42 of the reactor containment vessel 2 is opened, and the reactor pressure vessel 1 is suspended from the opened portion into the reactor containment vessel 2 by a crane and set to the reactor pressure vessel foundation 5. Thereafter, the lid 42 is closed, and the main steam pipe 32 is connected to the set reactor pressure vessel 1. Next, when the portion of the inner steel plate 14a and the outer steel plate 14b of the biological shielding wall 3 that has already been set on the base mat 15 is used as the lower stage of the biological shielding wall 3, the portion of the biological shielding wall 3 above the biological shielding wall 3 The upper stage, the upper steel plate of the living body shielding wall 3 is collectively suspended by a crane and stacked on the inner steel plate 14a and the outer steel plate 14b on the lower stage of the living body shielding wall 3, and the boundary is joined by welding. In this welding, since the horizontal interval between the inner steel plate 14a and the outer steel plate 14b is set to any dimension of about 1.5 meters to about 2 meters, the horizontal interval between the inner steel plate 14a and the outer steel plate 14b is set. A welding worker enters and welds the lower and lower joint ends of the biological shielding wall 3 of the inner steel plate 14a. The welding of the outer steel plate 14b may be performed with a welding worker entering the horizontal interval between the inner steel plate 14a and the outer steel plate 14b, or from the outside of the outer steel plate 14b. The inner steel plate 14a and the outer steel plate 14b are welded from one side.

  Further, the gap opened between the inner steel plate 14a and the outer steel plate 14b around the penetration 16 is closed with a steel plate so that the concrete liquid does not leak.

  After the steel plate portion of the biological shielding wall 3 is assembled by welding, the concrete liquid is injected between the inner steel plate 14a and the outer steel plate 14b, and the steel plate concrete is waited for the concrete liquid to solidify. It becomes a structure. The steel plate of the biological shielding wall 3 remains as it is and becomes a part of the biological shielding wall 3.

  The horizontal portion of the upper stage of the biological shielding wall 3 is made of a half SC structure. The half SC structure in this case means that the lower half of the horizontal portion is made of steel plate concrete and the upper half is made of reinforced concrete.

  In this way, the reactor containment vessel 2 and the biological shielding wall 3 are constructed, and each compartment or roof such as a plurality of rooms 33 and fuel storage pools 37 in which the equipment of the nuclear power plant is placed around the biological shielding wall 3. 39 is built.

  In this way, when the lower part of the biological shielding wall 3 is constructed of steel plate concrete, it is necessary to set a work space necessary for installation and removal of the concrete form between the biological shielding wall 3 and the reactor containment vessel 2. The horizontal gap 6 between the lower stage of the biological shielding wall 3 and the reactor containment vessel 2 can be set to a dimension between 50 mm and 300 mm.

Thus, the horizontal gap 6 between the lower stage of the biological shielding wall 3 and the reactor containment vessel 2 is 50 mm to
When it is as narrow as 300 mm, the heat applied from the reactor containment vessel 2 to the living body shielding wall 3 also increases, and the temperature of the horizontal gap 6 space tends to be low at the bottom and rise at the top. In order to prevent an increase in the thermal load on the reactor containment vessel 2 and the biological shielding wall 3, the following configuration is added as necessary.

That is, the living body shielding wall 3 facing the lower stage of the reactor containment vessel 2 has a gap between the room 33 adjacent to the living body shielding wall 3, the lower stage of the living body shielding wall 3, and the reactor containment vessel 2 as shown in FIG. Upper communication holes 5a and lower communication holes 5b communicating with the six spaces are provided in a vertically dispersed manner. As shown in FIG. 4, the upper communication hole 5a and the lower communication hole 5b have a flow path structure that is bent at right angles at two locations, and radiation from the reactor containment vessel 2 side communicates with the upper communication hole 5a. It is considered so that it does not go straight to the room 33 side through the hole 5b.

In such a structure, during normal operation of the reactor, the ambient temperature of the gap 6 portion between the reactor containment vessel 2 and the biological shielding wall 3 is the same as the ambient temperature in the reactor building 4 due to heat radiation from the reactor containment vessel 2. It is higher compared. If an upper communication hole 5a and a lower communication hole 5b for communicating the gap 6 and the reactor building 4 are provided at the upper and lower portions of the biological shielding wall 3 due to this temperature difference, the gap 6 passes through the upper communication hole 5a. Then, hot light air flows out to the room 33 side, and low temperature air flows from the lower communication hole 5b into the gap 6 part from the room 33 side. As a result of such natural convection, the atmosphere in the gap 6 part circulates without stagnation, the temperature and humidity of the gap 6 part are almost equalized in the room 33 of the reactor building 4, and heat is generated in the gap 6 part. The horizontal width dimension of the gap 6 can be reduced without being trapped.

  Further, by providing a plurality of upper communication holes 5a and lower communication holes 5b at the upper and lower parts of the biological shielding wall 3, the gap 6 can be ventilated and retention of high humidity air can be prevented. The performance deterioration of the sand cushion 9 provided at the bottom of the gap 6 can be suppressed. Furthermore, the heat released from the wall of the reactor containment vessel 2 in the event of a loss of coolant accidents raises the temperature of the surrounding biological shielding wall 3 and causes excessive thermal stress locally or entirely. Can be prevented.

  In the conventional design of the structural wall of the reactor building, since the design earthquake (S1 earthquake) after the loss of coolant accident was severe for the design of the biological shielding wall 3, the upper communication hole 5a and the lower communication hole 5b should be installed. Thus, the design load of the biological shielding wall 3 can be greatly reduced. As a result, during normal operation of the nuclear reactor, heat retention in the narrow gap 6 between the reactor containment vessel 2 and the biological shielding wall 3 is prevented, and moisture is collected in the sand cushion 9 part installed under the gap 6 part. It is possible to prevent the temperature increase in the gap 6 between the reactor containment vessel 2 and the biological shielding wall 3 and prevent excessive thermal stress from being applied to the biological shielding wall in the event of a coolant loss accident.

  Here, the biological shielding wall 3 can satisfy the radiation shielding function by making the flow path of the upper communication hole 5a and the lower communication hole 5b bent as shown in FIG. Further, since pool water is stored in the pressure suppression chamber 8 at the lower part of the reactor containment vessel 2 during the operation of the reactor, the water shielding function of radiation by this pool water is exhibited. It is acceptable to use a straight road structure.

  Depending on the structure of the reactor building 4, the above-described natural circulation may not occur due to the structural problem of each room 33 and the problem of airtightness. In such a case, as shown in FIG. 5, it is set as the structure which can produce the forced circulation of the atmosphere of gap 6 part using the air conditioner 7 placed in the room 33 of the reactor building 4. As shown in FIG. 5, the air flows into the air conditioner 7 from the room 33 that communicates with the upper communication hole 5 a, and the exhaust air from the air conditioner 7 is sent to the other room 33 below that communicates with the lower communication hole 5 b. By doing so, the atmosphere of the other room 33 flows from the other room 33 side toward the gap 6 through the lower communication hole 5b. By adopting such a configuration, as the entire gap 6 portion, the atmosphere of the gap 6 portion flows out from the upper communication hole 5a and flows in from the lower communication hole 5b, thereby creating a forced atmosphere circulation. it can. As a result of this forced circulation, the air in the gap 6 part is not trapped as in the case of natural circulation, the humidity is almost uniform in the reactor building 4, the heat load in each part is reduced and uniform, and the sand cushion It is possible to suppress the deterioration of the performance of the sand cushion 9 by preventing the 9 from containing excessive moisture.

Moreover, as shown in FIG. 6, by using the emergency gas treatment system 10 (SGTS) installed in the room 33 instead of the air conditioner 7, the atmosphere of the gap 6 part can be obtained even in an accident such as a coolant loss accident. Forced circulation can be generated between the room 33 and the excessive thermal load applied to the concrete member of the biological shielding wall 3 can be reduced. At this time, by forming a communication line 13 from the downstream side of the filter 12 of the emergency gas processing system 10 to the other room 33 that communicates with the lower communication hole 5b, the atmosphere of the gap 6 portion is made to be an emergency gas processing system. 10 flows into the room 33 with the upper communication hole 5a, the atmosphere is sucked into the emergency gas treatment system 10 by the blower 11 and passes through the filter 12 to the other room 33 through the communication line 13 configured by piping. The forced circulation is repeated, in which the atmosphere treated by the filter 12 is returned to the lower portion of the gap 6 through the lower communication hole 5b. As a result of this forced circulation, the atmosphere in the gap 6 is not confined, as in the case of natural circulation, and the humidity and temperature are substantially uniform in the reactor building 4, so that the walls of the biological shielding wall and the reactor containment vessel Reduction and uniformization of the thermal load can be achieved, and further, the sand cushion 9 can be made not to contain excessive moisture, so that deterioration of the performance of the sand cushion 9 can be suppressed. In addition, the fission product leaking outside from the reactor containment vessel 2 at the time of the coolant loss accident can be preferentially removed by the filter 12 of the emergency gas treatment system 10.

  According to such an embodiment of the present invention, the following features are listed.

  (1) The gap 6 width between the reactor containment vessel 2 and the biological shielding wall 3 can be reduced as much as possible (50 to 300 mm). That is, conventionally, between the reactor containment vessel 2 and the biological shielding wall 3, approximately 800 mm is necessary as a space that can be accessed by personnel from the viewpoint of securing a construction space for the biological shielding wall 3 construction. In the embodiment of the present invention, the living space shielding wall 3 is changed from the conventional reinforced concrete structure to the steel plate concrete structure, so that the construction space for the reactor containment vessel 2 and the living body shielding wall 3 can be reduced. The gap 6 with the living body shielding wall 3 can be reduced as much as possible (50 to 300 mm).

  Further, as shown in FIG. 2, when the steel plate of the reactor containment vessel 2 and the living body shielding wall 3 is made into the module 17, the gap 6 between the reactor containment vessel 2 and the living body shielding wall 3 is reduced, and maybe the living body. The diameter of the cylindrical shape of the steel plate of the shielding wall 3 is reduced, so that the module 17 can be made smaller and lighter. By using a conventional heavy lifting machine for construction, it is possible to effectively use the lifting machine. Reduction of the number of times of carrying in, shortening of the carrying-in period, etc. can be easily performed, and the construction cost can be reduced by reducing the number of man-hours associated therewith. Further, the horizontal gap of the gap 6 between the reactor containment vessel 2 and the biological shielding wall 3 is reduced, so that the reactor building 4 can be downsized and the construction process of the reactor building 4 can be shortened. It becomes possible.

  (2) When making the module 17 including the steel plate in the lower stage of the containment vessel 2 and the lower stage of the biological shielding wall 3, the upper end of the lower stage of the reactor containment vessel 2 protrudes above the upper end of the lower stage of the biological shielding wall 3. The height of the lower stage of the containment vessel 2 and the lower stage of the biological shielding wall 3 were adjusted. If it does in this way, at the time of welding joining with the lower stage of the containment vessel 2, and the upper stage of the containment vessel 2, the welding work space can be ensured reliably inside and outside of the containment vessel 2. Therefore, it is possible to easily cope with the welding of the reactor containment vessel 2 and the inspection of the welded portion, which are required to be welded from both the inside and outside. In this way, even when the gap 6 between the reactor containment vessel 2 and the biological shielding wall 3 is narrowed, the reactor containment vessel 2 can be welded and the welded portion can be inspected. The upper stage can be welded to the lower stage of the biological shielding wall 3.

  (3) In addition, the reactor containment vessel 2 performs various welding inspections at the time of construction and a final pressure test in order to confirm the soundness. In the pressure test, the containment vessel 2 was pressurized at a pressure 1.125 times the maximum operating pressure, and the pressure did not decrease as a whole. Had confirmed. In the embodiment of the present invention, the leak test can be replaced by a local leak test using a vacuum box for a site where the leak cannot be confirmed from the outside. In this local leakage inspection using a vacuum box, a vacuum box with a transparent window is placed on the test surface, the inside of the vacuum box is evacuated, and there is no gas passing from the outside of the reactor containment vessel 2 to the inside test surface. And a leakage inspection method that detects by detecting the formation of foam bubbles in the foaming liquid that has been applied to the test surface. When the gap 6 between the reactor containment vessel 2 and the biological shielding wall 3 is reduced as in the embodiment of the present invention, the reactor containment vessel 2 after the reactor containment vessel 2 and the biological shielding wall 3 are integrally suspended. In the welded portion, the gap 6 is small and access to the outer periphery of the lower part of the reactor containment vessel 2 is impossible for inspection workers, so it is difficult to confirm leakage after pressure resistance from the outside of the reactor containment vessel 2. However, in that case, it can be dealt with by performing the above-mentioned local leakage inspection with the vacuum box on the weld line from the inside of the reactor containment vessel 2.

  (4) In the steel reactor containment vessel 2, in the unlikely event of an accident, there is a possibility that the main body of the reactor containment vessel 2 will be affected by the thermal stress accompanying the temperature rise and pressure rise of the reactor containment vessel 2 There is. Therefore, in the lower part of the gap 6 between the reactor containment vessel 2 and the biological shielding wall 3 installed around the outer periphery of the reactor containment vessel 2, absorption of deformation due to thermal expansion of the reactor containment vessel 2 and the reactor containment vessel In order to release the thermal stress of 2, a sand cushion 9 made of sand is installed. However, when the gap 6 between the reactor containment vessel 2 and the biological shielding wall 3 is reduced, there is a possibility that the installation space for the sand cushion 9 cannot be secured. Therefore, as shown in FIG. 4, in order to secure an installation space for the sand cushion 9, a space for providing the sand cushion 9 is secured by cutting out the lower part of the biological shielding wall 3. Thereby, even when the gap 6 between the reactor containment vessel 2 and the biological shielding wall 3 is reduced, the sand cushion 9 can be installed. Moreover, since the notch part of the lower part of the biological shielding wall 3 is filled with sand, even if the biological shielding wall 3 has a notch, a major problem in the radiation shielding function of the biological shielding wall 3 does not occur.

  (5) Since the atmosphere in the gap 6 part between the reactor containment vessel 2 and the living body shielding wall 3 can be naturally circulated or forcedly circulated through the room 33 outside the living body shielding wall 3, the atmosphere in the gap 6 part is stagnant. In addition, both the temperature and the humidity are made almost uniform in the room 33 outside the living body shielding wall 3, and heat and moisture are not trapped in the gap 6 part. Therefore, it is not necessary to greatly secure the gap 6 as a countermeasure against heat and moisture. Moreover, the performance deterioration of the sand cushion 9 can be suppressed. Furthermore, it is possible to prevent excessive thermal stress from being generated by raising the temperature of the surrounding biological shielding wall 33 due to heat released from the wall of the reactor containment vessel 2 in the event of a coolant loss accident. Accordingly, the design load of the biological shielding wall 3 of the nuclear building can be greatly reduced.

  In addition, since the bent channel structure of the upper communication hole 5a and the lower communication hole 5b provided to promote the circulation of the atmosphere in the gap 6 part prevents the radiation from coming out linearly, The upper communication hole 5a and the lower communication hole 5b can be provided.

  (6) The installation of the reactor containment vessel 2 starts after the completion of the construction of the foundation mat 15, but work such as construction, testing and painting of the reactor containment vessel 2 body around the reactor containment vessel 2 Since it is necessary to secure space, the biological shielding wall 3 installed around the reactor containment vessel 2 is installed after the construction of the reactor containment vessel 2 is completed. The construction process of the containment vessel 2 and the biological shielding wall 3 is a critical process in the reactor building 4, but by adopting a steel plate concrete structure (SC structure) for the biological shielding wall 3 outside the reactor containment vessel 2, It is possible to make the module 17 of the steel plate member of the reactor containment vessel 2 and the biological shielding wall 3 in the construction site yard, improve the workability of the penetration 16 penetration portion, and the type inside the reactor containment vessel 2 and the biological shielding wall 3 Delete of construction space, the containment vessel 2 Construction and biological shield wall 3 translational of construction is possible.

  Further, since the biological shielding wall 3 has a steel plate concrete structure, the steel plate can be made much thinner than the steel biological shielding wall 3 and the weight of the module 17 is reduced. It is possible to suspend the steel plate member in the lower stage of the biological shielding wall 3 in a lump, and the construction process of the reactor building 4 can be shortened. As a method for suspending the module 17, as shown in FIG. 8, the suspension balance 19 prevents deformation of the entire module 17, the members constituting the module 17, and deformation of the module 17. Therefore, the reactor building 4 can be accurately constructed.

  As described above, by using the module 17, the construction process of the reactor building 4 can be shortened and the installation accuracy and reliability can be improved. In addition, the module 17 can be carried into the installation position using a large crane for construction, so that the large crane can be effectively used, the number of times of loading can be reduced, and the loading period can be shortened. The construction cost is reduced by the reduction.

  (7) The level of the division position in the height direction between the steel plate of the reactor containment vessel 2 and the steel plate of the biological shielding wall 3 and the division level of the steel plate of the reactor containment vessel 2 is the steel plate of the biological shielding wall 3. It is set higher than the division position. This contributes to securing a work space for welding and inspection of welded portions at the upper and lower ends of the division of the containment vessel 2. In the case where such divided parts are vertically shifted as one module 17 and suspended at the installation position, the vertical length of the steel mounting jig 23 to which the suspension balance 19 is fixed is adjusted. This will be possible. Thereby, the parallel construction of the reactor containment vessel 2 and the biological shielding wall 3 becomes possible, and the construction process of the reactor building 4 can be shortened.

It is a longitudinal cross-sectional view of the reactor building 4 by the Example of this invention. It is a perspective view of the module for construction by the example of the present invention. It is a longitudinal cross-sectional view of the sand cushion vicinity by the Example of this invention. It is a longitudinal cross-sectional view of the cooling mechanism of the natural circulation system of the gap part between the reactor containment vessel and the biological shielding wall by the Example of this invention. It is a longitudinal cross-sectional view of the cooling mechanism of the forced circulation system of the gap part between the reactor containment vessel and the biological shielding wall by the Example of this invention. It is a longitudinal cross-sectional view of the cooling mechanism of the other forced circulation system of the gap part between the reactor containment vessel and the biological shielding wall by the Example of this invention. It is the longitudinal cross-sectional view of the reactor building which showed the area | region of the reactor containment vessel lower part and the biological shielding wall lower part by the Example of this invention, and the area | region of the reactor containment vessel upper stage each enclosed with the broken line. FIG. 4 is a perspective view of a module integrated with a suspension balance according to an embodiment of the present invention. It is explanatory drawing which shows an example of the carrying-in procedure to the installation position of the reactor containment vessel and the biological shielding wall at the time of construction of the reactor building by the Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Reactor pressure vessel, 2 ... Reactor containment vessel, 3 ... Living body shielding wall, 4 ... Reactor building, 5a ... Upper communication hole, 5b ... Lower communication hole, 6 ... Gap, 7 ... Air conditioner, 8 ... Pressure Suppression chamber, 9 ... Sand cushion, 10 ... Emergency gas treatment system (SGTS) system, 11 ... Blower, 12 ... Filter, 13 ... Communication line, 14a ... Inner steel plate, 14b ... Outer steel plate, 15 ... Mat, 16 ... Penetration , 17 ... Module, 18 ... Reactor containment upper stage, 19 ... Suspension balance, 20 ... Wire rope, 21 ... Top slab, 22 ... γ-ray shielding wall, 23 ... Mounting jig.

Claims (7)

A steel plate containment vessel, a biological shield wall made of steel plate concrete surrounding the reactor containment vessel, and a 50 mm formed between the outer periphery of the cylindrical portion of the reactor containment vessel and the biological shield wall Reactor building with a gap of ~ 300mm width.   2. The nuclear reactor according to claim 1, wherein a sand cushion is installed between the nuclear reactor containment vessel and the biological shielding wall, and the width of the sand cushion in the radial direction of the nuclear reactor containment vessel is wider than the width of the gap. Building.   The reactor building according to claim 1, wherein the biological shielding wall is provided with holes vertically communicating with the gap and a space of the nuclear reactor building disposed outside the biological shielding wall.   The cylindrical first steel plate constituting the reactor containment vessel, and the inner cylindrical shape and the outer cylindrical multi-cylindrical second steel plate constituting the biological shielding wall made of steel plate concrete are made of the first steel plate. A module is arranged so that the second steel plate is positioned with a gap of 50 mm to 300 mm on the outer periphery, and the module is suspended and installed at the construction position of the reactor containment vessel and the biological shielding wall, The construction method of the reactor containment vessel and the part of the biological shielding wall above the module and the construction method of the reactor building in which concrete is injected between the inner and outer second steel plates.   5. The method of constructing a reactor building according to claim 4, wherein the module is configured by incorporating a pipe or cable penetration portion into the second steel plate, and the module is suspended and installed at a construction position.   6. The module according to claim 4, wherein the module is configured such that an upper end of the first steel plate is higher than an upper end of the second steel plate, and the module is formed between the reactor containment vessel and the biological shielding wall. A method of constructing a reactor building in which the steel plate of the reactor containment vessel above the first steel plate is welded and connected to the upper end of the first steel plate after being suspended in a construction position. 7. The reactor containment vessel and living body above the module according to claim 3, wherein the module and the equipment in the reactor containment vessel are installed after the module is installed. A method of constructing a reactor building in which a shielding wall portion is a ring-shaped structure and is installed above the module.

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